How to block domain sending alot of spam email to my distribution list

[mathayo]

Hi Team
I have tried to block the domain sender in /opt/zimbra/conf/postfix_reject_sender
then postmap the /opt/zimbra/conf/postfix_reject_sender
Finally did
zmprov mcf +zimbraMtaSmtpdSenderRestrictions "check_sender_access lmdb:/opt/zimbra/conf/postfix_reject_sender"

restarted the MTA
This is the email domain sending to my distribution list
MAILER-DAEMON@mail.ukdm.gov.za

but still coming.
Any idea to solve

[mathayo]

1. Create file /opt/zimbra/conf/postfix_reject_sender

mailer-daemon@mail.ukdm.gov.za REJECT
mail.ukdm.gov.za REJECT

2. postmap the file /opt/zimbra/postfix/sbin/postmap /opt/zimbra/conf/postfix_reject_sender

This creates /opt/zimbra/conf/postfix_reject_sender.lmdb

2. Set smtpd_sender_restrictions

Modify '''/opt/zimbra/conf/zmconfigd/smtpd_sender_restrictions.cf''', by adding this as the second line of the file:

%%contains VAR:zimbraMtaSmtpdSenderRestrictions check_sender_access lmdb:/opt/zimbra/conf/postfix_reject_sender%%

3. Execute:

zmprov ms <zmhostname> +zimbraMtaSmtpdSenderRestrictions "client_sender_access lmdb:/opt/zimbra/postfix/conf/postfix_reject_sender"

So.. which file/path is correct?

/opt/zimbra/postfix/conf/ or /opt/zimbra/conf/? If i use /opt/zimbra/postfix/conf/ i get an error

4. Execute:

zmmtactl stop && zmmtactl start


But seems still not working, email are coming approximately to 1000 email every single minute